Restraining mechanism for freepiston units



RESTRAINING MECHANISM FOR FREE-PISTON LII HTS 'Fileq Nov. 6, 1944 2She'ets-Sheec 1 FIG! W m. A. KALHTINSKY mww' Nov. 9, 1948. A.KALIVTINSKY 5 RESTRAINING MECHANISM- FOR FREE-PISTON mums Filed Nov. 6,1944 2 Sheets-Sheet 2 INVENTOR' Patented Nov. 9, I948 can-E STATES mambps-IC Application November 6, 194 1.,saaruatsam Theopposed pistons of afree-piston unit are nor-mally 'maintained at equaldistances from thecenter f the engine by a restraining linkage. 'i riecepnumg applicationof Ward, Serial No. 62 248jfiledN0vember 6, 1944, has a linkageincluding 'a "sleeve having right and lefthand threads engaging withcorresponding high-pitch threads on rods extending from the pistons. Afeature of 'this invention is 'the use of a pair of interconnectedsleeves, each of which is threaded for engagement by one of the pair ofrods extending from the opposed pistons.

'Anoiih'e'r feature -is the interconnection of the sleeve so that thesleeves may be similarly threaded. One of the sleeves may carry a camfor actuating an engine accessory. One feature of the invention is theuse of the two sleeves to permit a longer piston stroke withoutseriously lengthening the unit, since the ends of the rods may pass eachother during operation of the unit.

The rate of piston reciprocation is determined primarily by the mass ofthe moving elements of which the restraining linkage forms a part. Afeature of this invention is a linkage, the weight of which is easilychanged for varying the rate of piston reciprocation. The pair ofsleeves, which oscillate as the pistons reciprocate may be relativelyheavy, if desired, for a slow rate of piston reciprocation.

Other objects and advantages will be apparent from the specification andclaims, and from the accompanying drawing which illustrates what is nowconsidered a preferred embodiment of the invention.

Fig. l is a sectional view through the free-piston unit.

Fig. 2 is a fragmentary sectional view of the restraining mechanism.

The unit shown includes an engine cylinder having reciprocating pistonsl2 and M to which compressor pistons I6 and I8 in cylinders and 22 areintegrally connected. Sleeves 24 and 26 attached to the compressorpistons complete the reciprocating piston assemblies. The sleeves incombination with stationary pistons 28 and 30 form air spring cylinders.

The piston assemblies are moved apart by the burning of fuel injectedinto engine cylinder l0. Air compressed in the air spring cylinders onthe power stroke returns the piston assemblies.

Intake manifold 3 conducts air to intake valves 36 through which airalternately enters opposite ends of the compressor cylinders. Thecompressed air leaves the cylinders through discharge valves 38, also atopposite ends of the 6 Claims. (01. #4 57) compressor -cylinders, 'andpasses mpugn scavengeiiianifold 40 through *ports i-l and which areuncovered 'by pistons 12 and "M at the end ofthe power stroke, therebypermitting air to be blown through the 5 engine cylinder. Gasirom theengine cylinder discharges through exhaust ports 46 and 48 into exhaustmanifold 50.

LA *iiiechanis'm interconnects the piston assemblies to maintain"theinalways ateoual distances from the center of the engine cylinder.The linkage 'shownf'includes spaced parallel sleeves 52 '54 fo'taitab lysupported by bearings fidand 53 "and having intrhgaging gear teeth 6!]and 62 "for simultaneous rotation. sleeves 52 and '54 have triternnhighpitch tnreaa grdcvesfsa and E6 engaging with threads 68 and 1B onrods 12 and i4 extending from compressor pistons [l6 and Hi. If eitherpiston assembly tends to move out of phase, it is prevented by theinterconnected sleeves.

Either set of gear teeth or 62 may drive accessories such as theffuelpump or a cam 16 may be mounted on either of sleeves 52 or 54 fordriving an accessory, not shown.

The rate of piston reciprocation in afree-piston unit is dependentprimarily upon the weight of the moving masses of the unit. Since thesleeves, which oscillate as the pistons reciprocate, constitute a partof the moving mass, the rate of reciprocation of the unit may beadjusted by changing the weights of these sleeves.

Although only one restraining linkage has been described, it will beunderstood that a pair of these linkages may be used for balancing therestraining action on the opposed pistons.

It is to be understood that the invention is not limited to the specificembodiment herein illustrated and described, but may be used in otherways without departure from its spirit as defined by the followingclaims.

I claim:

1. A free-piston unit having opposed pistons, in combination with arestraining mechanism for said pistons, including a pair of rods, oneextending from each of the opposed pistons, a pair of rotary sleeves,one for each rod, said sleeves having interengaging means for rotationin unison and interengaging threads on the sleeves and the associatedrods for turning the sleeves as the rods are reciprocated with thepistons.

2. A free-piston unit having opposed pistons, in combination with arestraining mechanism for said pistons, including a pair of, rods, oneextending from each of the opposed pistons, a pair of rotary sleeves,one for each rod, said sleeves having interengaging means for rotationin unison and interengaging threads on the sleeves and the associatedrods for turning the sleeves as the rods are reciprocated with thepistons, one of said sleeves having accessory actuating means thereon.

3. A restraining mechanism for the opposed pistons of a free-pistonunit, said mechanism including a pair of rods, one extending from eachpiston, a pair of rotary sleeves, one for each rod, said sleeves beingparallel to each other and having interengaging means for rotation inunison, interengaging threads on the rods and sleeves for turning thesleeves as the rods are reciprocated with the pistons and means forsupporting the sleeves in fixed axial position.

4. A restraining. mechanism for the opposed pistons of a free-pistonunit, said mechanism including a pair of rods, said rods being parallel,and one extending from each piston, a pair of rotary sleeves, one foreach rod, said sleeves having interengaging means for rotation inunison, interengaging threads on the sleeves and the associated rods forturning the sleeves as the rods are reciprocated with the pistons andmeans for supporting the sleeves in fixed axial position.

5. A restraining mechanism for the opposed pistons of a free-pistonunit, said mechanism including a pair of parallel rods extendin towardeach other from the opposed pistons, a pair of sleeves engageable bysaid rods, said sleeves having interengaging means for rotation inopposite directions, each sleeve having similarly arranged threadsthereon, cooperating threads on the associated rods for turning thesleeves as the rods are reciprocated with the pistons and means forsupporting the sleeves in fixed axial position.

Number sociated rods for turning the sleeves as the rods arereciprocated with the pistons, one of said sleeves having a cam foractuating an accessory for the unit and means for supporting the sleevesin fixed axial position.

ANDREW KALITINSKY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Eccler 1 July 11, 1876 Roebling Oct. 12,1897 Robson July 27, 1915 Junkers Mar. 5, 1929 Junkers July 30, 1929Janicke Nov. 19, 1940 De Veau Dec. 16, 1941 Pescara Mar, 14, 1944FOREIGN PATENTS Country Date Italy Mar. 5, 1939 Number

